Most of the standard refactorings that ReSharper provides for other languages are available for ASP.NET as well. For more information about them and how they can be applied, see Refactorings.
A bit more powerful is the Change Signature refactoring. In addition to renaming a symbol this refactoring allows you to add, remove or rearrange parameters of a method. For more information, see Change Signature.
Move to Resource
ASP.NET enables you to create pages that can change content depending on the explicit choice of language, for example. Content and other data are stored in resource files and can be accessed easily using the appropriate resource expressions. If there are some strings, texts hidden in markup, ReSharper helps you find them and accurately transfer to the appropriate resource files without unnecessary complications.
As usual, you just press Ctrl+Shift+RCtrl+Shift+R to display the list of all available refactorings and choose the desired one.
Safe Delete Resource
As soon as you've noticed that some resource is useless, you can invoke the Safe Delete Resource refactoring and remove it immediately.
For more information, see Localization Assistance: Refactorings.